Handle bytecode without IC state

Deserialized bytecode does not have IC state, i.e., `bc->ic == NULL`.
That may or may not be bug (IMO, it is and we should rebuild the
IC state during deserialization) but, either way, don't segfault.

DRY add_ic_slot() and its call sites in a hopefully NFC manner.

Author: bnoordhuis

quickjs-libc.c

@@ -832,11 +832,12 @@ static JSValue js_evalScript(JSContext *ctx, JSValue this_val,
 {
     JSRuntime *rt = JS_GetRuntime(ctx);
     JSThreadState *ts = JS_GetRuntimeOpaque(rt);
-    const char *str;
+    const char *str = NULL;
     size_t len;
-    JSValue ret;
+    JSValue ret, obj;
     JSValue options_obj;
     BOOL backtrace_barrier = FALSE;
+    BOOL eval_function = FALSE;
     BOOL compile_only = FALSE;
     BOOL is_async = FALSE;
     int flags;
@@ -846,6 +847,9 @@ static JSValue js_evalScript(JSContext *ctx, JSValue this_val,
         if (get_bool_option(ctx, &backtrace_barrier, options_obj,
                             "backtrace_barrier"))
             return JS_EXCEPTION;
+        if (get_bool_option(ctx, &eval_function, options_obj,
+                            "eval_function"))
+            return JS_EXCEPTION;
         if (get_bool_option(ctx, &compile_only, options_obj,
                             "compile_only"))
             return JS_EXCEPTION;
@@ -854,9 +858,11 @@ static JSValue js_evalScript(JSContext *ctx, JSValue this_val,
             return JS_EXCEPTION;
     }
 
-    str = JS_ToCStringLen(ctx, &len, argv[0]);
-    if (!str)
-        return JS_EXCEPTION;
+    if (!eval_function) {
+        str = JS_ToCStringLen(ctx, &len, argv[0]);
+        if (!str)
+            return JS_EXCEPTION;
+    }
     if (!ts->recv_pipe && ++ts->eval_script_recurse == 1) {
         /* install the interrupt handler */
         JS_SetInterruptHandler(JS_GetRuntime(ctx), interrupt_handler, NULL);
@@ -868,7 +874,12 @@ static JSValue js_evalScript(JSContext *ctx, JSValue this_val,
         flags |= JS_EVAL_FLAG_COMPILE_ONLY;
     if (is_async)
         flags |= JS_EVAL_FLAG_ASYNC;
-    ret = JS_Eval(ctx, str, len, "<evalScript>", flags);
+    if (eval_function) {
+        obj = JS_DupValue(ctx, argv[0]);
+        ret = JS_EvalFunction(ctx, obj); // takes ownership of |obj|
+    } else {
+        ret = JS_Eval(ctx, str, len, "<evalScript>", flags);
+    }
     JS_FreeCString(ctx, str);
     if (!ts->recv_pipe && --ts->eval_script_recurse == 0) {
         /* remove the interrupt handler */

quickjs.c

@@ -7362,9 +7362,8 @@ static JSValue JS_GetPropertyInternal2(JSContext *ctx, JSValue obj,
                     continue;
                 }
             } else {
-                if (icu && proto_depth == 0 && p->shape->is_hashed) {
+                if (proto_depth == 0)
                     add_ic_slot(ctx, icu, prop, p, offset);
-                }
                 return js_dup(pr->u.value);
             }
         }
@@ -8658,9 +8657,7 @@ static int JS_SetPropertyInternal2(JSContext *ctx, JSValue obj, JSAtom prop,
         if (likely((prs->flags & (JS_PROP_TMASK | JS_PROP_WRITABLE |
                                   JS_PROP_LENGTH)) == JS_PROP_WRITABLE)) {
             /* fast case */
-            if (icu && p->shape->is_hashed) {
-                add_ic_slot(ctx, icu, prop, p, offset);
-            }
+            add_ic_slot(ctx, icu, prop, p, offset);
             set_value(ctx, &pr->u.value, val);
             return TRUE;
         } else if (prs->flags & JS_PROP_LENGTH) {
@@ -54516,10 +54513,19 @@ static void add_ic_slot(JSContext *ctx, JSInlineCacheUpdate *icu,
 {
     int32_t i;
     uint32_t h;
-    JSInlineCache *ic = icu->ic;
     JSInlineCacheHashSlot *ch;
     JSInlineCacheRingSlot *cr;
+    JSInlineCache *ic;
     JSShape *sh;
+
+    if (!icu)
+        return;
+    ic = icu->ic;
+    if (!ic)
+        return;
+    sh = object->shape;
+    if (!sh->is_hashed)
+        return;
     cr = NULL;
     h = get_index_hash(atom, ic->hash_bits);
     for (ch = ic->hash[h]; ch != NULL; ch = ch->next) {
@@ -54528,21 +54534,17 @@ static void add_ic_slot(JSContext *ctx, JSInlineCacheUpdate *icu,
             break;
         }
     }
-
     assert(cr != NULL);
     i = cr->index;
-    for (;;) {
-        if (object->shape == cr->shape[i]) {
+    do {
+        if (sh == cr->shape[i]) {
             cr->prop_offset[i] = prop_offset;
             goto end;
         }
         i = (i + 1) % countof(cr->shape);
-        if (unlikely(i == cr->index))
-            break;
-    }
-    sh = cr->shape[i];
-    cr->shape[i] = js_dup_shape(object->shape);
-    js_free_shape_null(ctx->rt, sh);
+    } while (i != cr->index);
+    js_free_shape_null(ctx->rt, cr->shape[i]);
+    cr->shape[i] = js_dup_shape(sh);
     cr->prop_offset[i] = prop_offset;
 end:
     icu->offset = ch->index;

tests/test_bjson.js

@@ -230,7 +230,7 @@ function bjson_test_symbol()
 
 function bjson_test_bytecode()
 {
-    var buf, o, r, e;
+    var buf, o, r, e, i;
 
     o = std.evalScript(";(function f(o){ return o.i })", {compile_only: true});
     buf = bjson.write(o, /*JS_WRITE_OBJ_BYTECODE*/(1 << 0));
@@ -241,10 +241,10 @@ function bjson_test_bytecode()
     }
     assert(String(e), "SyntaxError: no bytecode allowed");
 
-    // can't really do anything with |o| at the moment,
-    // no way to pass it to JS_EvalFunction
     o = bjson.read(buf, 0, buf.byteLength, /*JS_READ_OBJ_BYTECODE*/(1 << 0));
     assert(String(o), "[function bytecode]");
+    o = std.evalScript(o, {eval_function: true});
+    for (i = 0; i < 42; i++) o({i}); // exercise o.i IC
 }
 
 function bjson_test_fuzz()